Marelli Microplex for biturbo

[fphil]

Indeed it is a slow project. My Maserati biturbo my 1987 is now working fine and I am actually looking inside the eprom of ignition ECU (Marelli Microplex 602F).
From time to time I play with the Vems Ecu on a bench which is easy now thanks to Vemstune.

The engine car is 6 cylinders odd fire, sequence for ignition is 150°-90°-150°-90°-150-90°.

Triggers are 6 pins (30°-90°-30°-90°-30°-90°) on crank pulley, 2 pins on cam pulley 25° apart.

I made a .wav file for testing
https://docs.google.com/leaf?id=0Bzteg8lQJZdWYmQ3ZTA3YjctZGY5Yy00NTc5LWE1OWQtOTljMmY5YjRkYTg1&hl=en&authkey=CJTa1IoG.

Does anyone know if Vems firmware is able to track this profile?

[fphil]

I read the last posts last dated 2008 concerning oddfire. There may be new capabilities for the firmware since then.

So may be some one in the community, who knows the firmware or better had written part of it, may reply to the following simple and apparently unsophisticated question :

Is the firmware good for coil trigger + 6 cylinders oddfire engine

Cheers

Philippe

[mattias]

I would make sure the sensors are Hall type, and cut one pin on the cam pulley.

The crank trigger pattern sounds plausible.. but not tested. Chances are it works, but you would be better off with a missing-tooth wheel like a 36-1 (which matches up with 150°-90° pattern).

Could've made a brain fart but something like this should work, depending on where cam sync occurs :

Each tooth add degrees:  30-90-30, 90, 30-90-30, 90, 30-90-30, 90
Which makes this pattern : 150, 90 , 150, 90, 150, 90
Trigger teeth are : 0,3,4,7,8,11

[fphil]

Thanks Matthias for your answer.

The sensors  are VR but it is not a big problem to make a Hall signal from them or to get it from the Marelli board.

I can filter out one of the crank trigger or even I can divide the triggers by two to make 2 x (1cam trig +3 crank trig) each for one even fire 3 cylinders, for respectively the left bank and the right bank of the engine . But in this last case I need 2 GenBoards !!!
This is what Maserati has done for the late biturbos: 2 triggers + one ecu (ignition+injection) for each bank

I would like to keep along with the original cam and crank pulleys since my first step woud be to replace the ignition Marelli ECU which also control the boost, and keep, for a while, the Weber injection ECU (each ecu controls the 2 banks for the previous biturbos)

Hence my concern for coil type trigger ...

I guess the bottleneck is for the firmware to get the angle velocity for appropriate timing

Philippe

[mattias]

Yes, the hard part is different time between teeth, like I said your best bet is to install a 36-1 wheel on the crank, you don't have to worry about timing with that solution:  simply 15 and then 9 teeth, alternating until cam sync.

[fphil]

like I said your best bet is to install a 36-1 wheel

Yes, you are probably right. I would be easier to modify the pulley crank or even to set a sensor for the other cam pulley.
I should think to work on this way;

Philippe

[fphil]

Hurrah, thanks to Marcell we have got a new page here
http://www.vems.hu/wiki/index.php?page=MembersPage%2FOddFireSixCyl
and a dedicated biturbo odd fire firmware version 1.1.90 to exercise !

Alas! the secondary trigger of my GenBoard 322, my 2005, is Hall.

So I followed the "Official build and test guide" §2.2.5. I soldered an LM1815 component and, as said appendix 4.1 on page 18, I set the blob bridge and the wire. Although I was not able to fully rely this modif with an understanding of the electronic schematic.

Further I tested version1.1.90. Did not run. (but it runs when 2nd rigger Camsync is disable).

Do someone knows
- a simple software procedure to test the VR secondary trigger
- if the modif described by the documentation is completely relevant?

Thanks a lot

Philippe